Hydraulic door closer and hold-open device



June 18, 1963 R. F. TRASK HYDRAULIC DCCR CLOSER AND HOLD-OPEN DEVICE Filed July 28, 1960 INVENToR. lussell F Euski It.

Dm um United States Patent O 3,093,858 HYDRAULIC DOR CLOSER AND HOLD-GPEN DET/ECE Russell F. Trask, 3.94 Ridge Ave., Crystal Lake, Ill. Filed July 28, 1960, Ser. No. 45,912 13 Claims. (Cl. 16--54) This invention relates to a hydraulic door closer, that functions as a door check and is readily convertible also to a hold-open device, the invention having -fo-r its principal object the provision of a simple and economical device `of the kind mentioned easily applicable to the inner side of most any hinged door directly over one of the hinge pintles.

In the device of my invention, a small bracket for pivotal support of one end of the hydraulic cylinder is adapted to be mounted by means of the hinge pintle on 'top of one ofthe hinges, using the fixed butt of said hinge 'as `an abutment for a lug on the bracket to hold the latter against turning about the hinge pintle as a center, the piston in the hydraulic cylinder, which is pivotally connected a-t the outer end of its -rod to the door and Iis movable in the door opening direction quickly against the resistance of a coiled compression spring, that is cornpressed in this movement, While the liquid in the cylinder `is bypassed from in front of the piston to behind it past an open check valve in the piston, being returned slowly under recoil action of the spring as the liquid in the cylinder bleeds back slowly through a bleeder port past the seated check valve in the piston from behind the piston to the cylinder space housing the spring in front of the piston.

If the door frame is not cu-t away to allow swinging movement of the lug on the pintle receiving end of the bracket about the hinge pintle as a center, the device can function only las a door closer, :as above described. However, by merely notching the door frame -behind the bracket lug :so that when the door is opened to a 90 position it is only necessary to apply a little pressure to the outer end 'of the bracket Where it has the end of the cylinder pivotally connected thereto to throw the bracket past dead center to make the device function :as a door hold-open until the bracket is swung back to the former position again.

A bracket, which serves as a combined holddown and brace for the hinge pin is also provided adapted to be fastened to the door frame, having one lug on its outer end extending over the head of the hinge pintle to hold it down, so that it cannot drift out, while another lug has :abutment with the side of the head to assume side thrust and thusrelieve the hinge from the load incident to the operation of the door closer, to minimize likelihood of the hinge working loose.

A neat and attractive channel shaped enclosure is also provided for the door closer that has a press tit over the cylinder and conceals much of the lirst mentioned hinge pintle bracket 'and all the res-t of the assembly but is quickly and easily removable for access to the door closer.

The invention is illustrated in the accompanying drawing, in which:

FIG. l is a plan View of a hydraulic doo-r closer made in accordance with my invention, portions of the channel shaped sheet metal enclosure being broken -away to better disclose the hingle pintle `attaching and mounting bracket at `one end and the door attached channel bracket at the other end, the latter -being shown in horizontal section;

FIG. 2 is a front view of the device, showing most of the enclosure in longitudinal section to expose the cylinder and piston, `a portion of the cylinder being also shown 4in longitudinal section along with the piston to 3,093,858 Patented .lune 18, 1963 ice enable a better understanding of the construction and mode of operation, and

FIGS. 3, 4 and 5 are perspective views, respectively, of the door-attached channel bracket, combined hinge pin hold-down and brace bracket, and the hinge pin attached bracket.

The same reference numerals are applied to correspending parts in these tive views.

Referring to the drawing, the cylinder 11 contains a piston :112, the rod 13 of which extends through a center hole lin ya plug 14 suitably secured in the end of the cylinder wherein an O-ring 15 is provided to prevent leakage of oil or other fluid in the reciprocation of the piston. A coiled compression spring 16 is disposed between the piston i12 and the inner end of the cylinder 11 and is compressed in the opening of the door D as piston 12 moves inwardly. Oil from in front of the piston flows freely through port 18a past la check valve 17 through radial ports 1811 so that there is virtu-ally nothing but spring 16 to interfere with the opening of the door, but when the door closes under pressure of spring y16, the oil seats the check valve 17 on port 18a and flows slowly through a bleeder port 19 in the piston, thereby slowing the return movement.

A bracket 20 is pivotally connected by pin 21 to the end of the cylinder 11. Bracket 20 has a hole 22 in it `throught which the hinge pin 23 of the door hinge 24 is entered to assemble onto the hinge With the lug 25 that extends downwardly from bracket 2() disposed behind the one -xed butt 26 of the hinge to hold the bracket against turning in a clockwise direction, as seen in the top View, FIG. 1. Another bracket 27 fastened by screws 28 onto the door trim :or frame F has one lug 29 projecting over the head 0f the pin 23 to lrold it down while another lug l30 has abutment with the side of the head to assume lateral thrust and reduce likelihood of the hinge loosening `due to the pressure of the door closer on the hinge 24.

Rod 13 is pivotally connected at 31 to the channel bracket 32 fastened to the door, as by screws 33, and a channel-shaped sheet metal cover 34 encloses the entire [device for neater appearance, the cylinder 11 being pressed tightly between the opposed walls 35. This method of assembly enables doing lall of the installation work before the cover 34 is applied.

A slot 36 is provided in one end wall 37 of cover 34 providing operating clearance for bracket 20. When the door is swung open to a position with piston rod 13 in line with pins 21 and 23, the door will be held open by reason of the parts being in dead-center relationship, which is loften an advantageous feature. Then, if the operator Wants to prevent accidental closing of the door `for a while he can swing the bracket 20 in a counterclockwise direction, as indicated by the dotted line position in FIG. l, if the door trim or frame F has been cut away at 38 to all-ow the lug 25 to move in the counterclockwise direction to the extent indicated in `dotted lines in FIG. 1. The bracket 20, striking the inner end of the slot 36, is limited in its cooking movement and will then remain cocked with the spring 16 compressed and piston 12 all the way in, substantially the same as for the fully opened 90 position of the door. Now, if the frame F has been cut away enough to allow full 90 or more `of movement of lug 25, the door can be closed and opened freely the same as if the door close-r were absent or removed. It is, however, a simple matter to uncock the bracket 20 back to the normal position shown in full lines, whereupon the door closer resumes its normal functioning. It is believed that most users of this device will prefer cutting away at 38 only about 45 or less rather than the full 90 shown even if doing so means sacrificing the devices ont-off feature. In many installations, the spacing of the trim F relative to the hinges is such that there is no need for any cutting away, as at 38, because there is ample operating clearance for -lug 25 to permit cocking bracket 2%, as shown in dotted lines in FIG. 1.

In operation, after the installation of the door closer and hold-open device, if the bracket 32 is found to have been fastened onto the door D (or other closure) too close to the hinges 24, or too far away, it is `a `simple matter t remove the pin 31 and shift the -bracket laterally one way or the other to the correct location, and usually the extra pair of holes 38 in the web 39 of the channel of said bracket obviate the necessity for drilling additional holes in the door. When the parts are properly located with respect to one another, piston 12 is moved freely to the left in the cylinder 11 in the opening of the door D as the oil or other liquid in front of the piston passes the check valve 17 and flows through ports 18o and 18!) into the other end of the cylinder, the spring 16 meanwhile being compressed to provide the door closing force. In fully opened position, pin 31 may closely approach a deadcenter relationship with respect to pin 21 and pintle 23, but it is only when the door is at 90 to frame F and bracket 2i) is purposely swung in a counterclockwise direction Vabout pintle 23 .as a center that pin 21 is to the right of a line through pin 31 and pintle 23, so that the device functions as `a hold-open. Otherwise, it closes the door slowly under recoil action of spring 16, the slow return movement of piston 12 being due to the restriction of oil fiow back through bleeder port i9 on the piston, check valve 17 being held closed under oil pressure. When the bracket 20 has been thrown to the over-center position mentioned above, the door is held open positively only as long as the operator leaves this bracket in that position. When he returns the bracket 20 to its normal position, the dev-ice functions lagain as a door closer. The device usually does not necessitate the hiring of a carpenter but is easily installaible by the average handy man or do-it-yourselfer when a few simple installation instruct-ions are furnished with each device.

It is believed the foregoing description conveys a good understanding of the objects and advantages of my invention. The appended claims have been drawn to cover all legitimate modifications and adaptations.

' I claim:

1. In a device of the character described, a cylinder containing an incompressible fluid, a piston reciprocable in said cylinder having a rod extending from one end of said cylinder through a guide opening provided therein, whereby 4chambers to contain said uid are defined in said cylinder on opposite sides of said piston, a coiled compression spring compressible between the other end of said cylinder and said piston, means `for pivotally connecting the outer end of said rod and the remote end of said cylinder to a door and a door frame, respectively, said piston having a port provided therein through which relatively unrestricted communication is afforded through the piston with the chambers on opposite sides thereof, there being another port provided in said piston affording relatively restricted communication through said piston between .said chambers on opposite sides thereof, and a check valve housed in said piston for closing the first mentioned port, said check va-lve moving toward said spring to close said port, the means for pivotally connecting the remote end of said cylinder to the `door frame comprising a bracket having a cylinder pivot on one portionV thereof and having means provided on another portion thereof spaced from the cylinder pivot and adapted to 'be attached to a door hinge, whereby to pivotally conneet the cylinder with the door frame on which the hinge is mounted with the pivot spaced radially outwardly from the hinge and hinged edge of the door, the bracket having an opening provided therein to receive the hinge pintle and having a lug projecting therefrom for engagement behind the fixed butt of the door hinge in radially spaced relationship to the pintle to prevent pivotal movement of said bracket with respect to said pintle in one direction.

2. In a device of the character described, a cylinder containing an incompressible fluid, a piston reciprocable in said cylinder having a rod extending from one end of said cylinder through a guide opening provided therein, whereby cham-bers to contain said fluid are defined in said cylinder on opposite sides of said piston, a coiled compression spring compressible between the other end of said cylinder and said piston, means for pivotally connecting the outer end of -said rod and the remote end of said cylinder to a door and a door frame, respectively, said piston having `a port provided therein through which relatively unrestricted communication is afforded through the piston with the chambers on opposite Vsides thereof, there being another port provided in said piston affording relatively restricted communication through said piston between said chambers on opposite sides thereof, and a check valve housed in said piston for closing the first mentioned port, said check valve moving toward said spring to close said port, the means for pivotally connecting the remote end of said cylinder to the ydoor `frame comprising a bracket having a cylinder pivot on one portion thereof and having means provided on another portion thereof spaced from the cylinder pivot `and adapted to be attached to a door hinge, whereby to pivotally connect the cylinder with the door fname on which the hinge is mounted with the pivot :spaced radially outwardly from the hinge and hinged edge of the door, the bracket having an opening provided therein to receive the hinge pintle and having a lug projecting therefrom for engagement behind the fixed butt of the door hinge in radially spaced relationship to the pintle to prevent pivotal movement of said bracket with respect to said pintle in one direction, there being means on the door frame spaced from said lug limiting pivotal movement of said bracket relative to said pintle in the opposite direction.

3. In a device of the character described, a cylinder containing an incompressible fluid, a piston reciprocable in said cylinder having a rod extending from one end of said cylinderV through a guide opening provided therein, whereby chambers to contain said fluid are defined in said cylinder on opposite sides of said piston, a coiled compression spring compressible between the other end of said cylinder and said piston, means for pivotally connecting the outer end of said rod and the remote end of said cylinder to a `door and a door frame, respectively, said piston having a port provided therein through which relatively unrestricted communication is afforded through the piston with the chambers on opposite sides thereof, there being another port provided in said piston aiording relatively restricted communication through said piston between said chambers on opposite sides thereof, and a check valve housed in said piston for closing the first mentioned port, said check valve moving toward said spring to close said port, the means for pivotally connecting the remote end of said cylinder to the door frame comprising a bracket having a cylinder pivot on one portionr thereof and having means provided on another portion thereof spaced from the cylinder pvot land adapted to be attached to a door hinge, whereby to pivotally connect the cylinder with the door fname on which the hinge is mounted' with the pivot spaced radially outwardly from the hinge and` hinged edge of the door, the bracket having an opening provided therein to receive the hinge pintle and having a lug projecting therefrom for engagement behind the fixed butt of the door hinge in radially spaced relationship Vto the pintle to prevent pivotal movement of said bracket with respect to said pintle in one direction, the door frame being cut away in the path of said lug in the pivotal movement of said bracket about said pintle in the opposite direction to limit the angularity of pivotal movement of said bracket in that direction.

4. In a device of the character described, a cylinder containing an incompressible fluid, Aa piston reciprocable in said cylinder having a rod extending from one end of said cylinder through a guide opening provided therein,

whereby chambers to contain said fluid are defined in said cylinder on opposite sides of said piston, a coiled compression spring compressible between the other end of said cylinder and said piston, means for pivotally connecting the outer end of `said rod and the remote end of said cylinder to a door and a door trame, respectively, said piston having a port provided therein through which relatively unrestricted communication is afforded through the piston with the chambers ou opposite sides thereof, there being another port provided in said piston aifording relatively restricted communication through said piston between said chambers on opposite sides thereof, and a check valve housed in said piston for closing the first mentioned port, said check valve moving toward said -spring to close said port, the means for pivotally connecting the remote end of said cylinder to the `door frame comprising a bracket having a cylinder pivot on .one portion thereof and having means provided on another portion thereof spaced from the cylinder pivot and adapted to be attached to a door hinge, whereby to pivotally connect the cylinder with the door frame on which the hinge is mounted with the pivot spaced radially outwardly from the hinge and hinged edge of the door, the bracket having an opening provided therein to receive the hinge pintle and having a lug projecting therefrom for engagement behind the fixed butt of the door hinge in radially spaced relationship to the pintle to prevent pivotal movement of said bracket with respect to said pintle in one direction, said bracket being free to turn relative to said pintle in the opposite direction, there being means in rigid relationship to said cylinder engageable with said bracket positively limiting its pivotal movement in the latter direction so as to limit the extent to which the cylinder pivot on said bracket may be thrown off dead center with respect to a line through the hinge pintle and pivotal connection for the outer end of said rod on said door.

5. ln a device of the character described, a cylinder containing an incompressible uid, a piston reciprocable in said cylinder having `a rod extending from one end of said cylinder through a guide opening provided therein, whereby chambers to contain said fluid are defined in said cylinder on opposite sides of said piston, a coiled compression spring compressible between the other end of said cylinder and said piston, means for pivotally connecting the outer end of said rod and the remote end of said cylinder to 'a door and a door frame, respectively, said piston having a port provided therein through which relatively unrestricted communication is afforded through the piston with the chambers on opposite sides thereof, there being another port provided in said piston affording relatively restricted communication through said piston between said chambers on opposite sides thereof, and a check valve housed in said piston for closing the first mentioned port, said check Valve moving toward said spring to close said port, the means for pivotally connecting the remote end of said cylinder to the door frame comprising a bracket having a cylinder pivot on one portion thereof and having means provided on another portion thereof spaced from the cylinder pivot and adapted to be attached to 'a door hinge, whereby to pivotally connect the cylinder with the door frame on which the hinge is mounted with the pivot spaced radially outwardly from the hinge and hinged edge of the door, the cylinder pivot on said bracket being so located with respect to the hinge pintle and the pivotal connection for the outer end of the piston rod on the door that when the door is swung open through approximately 90 the cylinder pivot and the pivotal connection for the rod with the door are aligned with the hinge pintle in dead center relationship, whereby the door may be held open in that position so long as the three points remain aligned.

6. In a device of the character described, a cylinder containing an incompressible fluid, a piston reciprocable in said cylinder having `a rod extending from one end of said cylinder through a guide opening provided therein, whereby chambers to contain said fluid are defined in said cylinder on opposite sides of said piston, a coiled compression spring compressible between the other end of said cylinder and said piston, means for pivotally connecting the outer end of said rod and the remote end of said cylinder to ya door and a door frame, respectively, said piston having a port provided therein through which relatively unrestricted communication is afforded through the piston with the chambers on opposite sides thereof, there being another port provided in said piston affording relatively restricted communication through said piston between said chambers on opposite sides thereof, and a check valve housed in said piston for closing the iirst mentioned port, said check valve moving toward said spring to close said port, the means for pivotally connecting the remote end of said cylinder to the door frame comprising a bracket having a cylinder pivot on one portion thereof and having means provided on another portion thereof spaced from the cylinder pivot and adapted to be attached to a door hinge, whereby to pivotally connect the cylinder with the door frame on which the hinge is mounted with the pivot spaced radially outwardly from the hinge and hinged edge of the door, the cylinder pivot on said bracket being s0 located with respect to the hinge pintle and the pivotal connection for the outer end of the piston rod on the door that when the door is swung open through approximately 90 the cylinder pivot and the pivotal connection for the rod with the door are aligned with the hinge pintle in `dead center relationship, whereby the door may beheld open in that position so long as the three points remain aligned, said bracket having an opening provided therein to receive a hinge pintle and there being a lug on said bracket engaging behind the iixed butt of said hinge to prevent pivotal movement of said bracket in one direction, but said bracket being oscillatable with respect to said hinge pintle through a small angle in the opposite direction, whereby to permit movement of the cylinder pivot on said bracket away from dead center suliiciently to lock the door in the extreme open position.

7. ln a device lof the character described, a cylinder containing an incompressible iiuid, `a piston reciprocable in said cylinder having a rod extending from one end of said cylinder through a guide opening provided therein, whereby chambers to contain said fluid are deined in said cylin- ,V der on opposite sides of said piston, a coiled compression spring compressible between the other end of said cylinder and said piston, means for pivotally connecting the outer end of said rod and the remote end of said cylinder to a door and a door frame, respectively, said piston having a port provided therein through which relatively unrestricted communication is afforded through the piston with the chambers on opposite sides thereof, there being another port provided in said piston affording relatively restricted communication through said piston between said chambers on opposite sides thereof, and a check valve housed in said piston for closing the iirst mentioned port, said check valve moving toward said spring to close said port, the means for pivotally connecting the remote end of said cylinder to the door frame comprising a bracket having a cylinder pivot on one portion thereof and having means provided on another portion thereof spaced from the cylinder pivot and Iadapted to be attached to a door hinge, whereby to pivotally connect the cylinder with the door frame on which the hinge is mounted with the pivot spaced radially outwardly from the hinge and hinged edge of the door, the cylinder pivot on said bracket being so located with respect to the hinge pintle and the pivotal connection for the outer end of the piston rod on the door that when the door is swung open through approximately the cylinder pivot an-d the pivotal connection for the rod with the door lare aligned with the hinge pintle in dead center relationship, whereby the door may be held open in that position so long as the three points remain aligned, said bracket having an opening provided therein to receive a hinge pintle and there being a lug on said bracket engaging behind the iixed butt of said hinge to prevent pivotal movement of said bracket in one direction, said bracket being free to turn relative to said pintle in the opposite direction but there being means rigid with the cylinder engageable with said bracket positively limiting its pivotal movement in the latter direction so as to limit the extent to which the cylinder pivot on said bracket may be thrown off dead center with respect to a line through the hinge pintle and pivotal connection for the outer end of said rod on said door.

8. A device as set forth in claim 1 wherein the device is applicable to a door mounted in a door frame on hinges, each of which comprises a fixed butt on the door frame pivotally connected by means of a pintle with a butt secured to the door, and another bracket fastened to the door frame adjacent said hinge engaging the head end of the pintle toV limit upward displacement of said pintle and assume side thrust of the cylinder on the hinge.

9. A device as set forth in claim 1 wherein the device is applicable to a door mounted in a door frame on hinges, each of which comprises a fixed butt on the door frame pivotally connected by means of a pintle with a butt secured to the door, and a bracket secured to the door frame behind the hinge and above the first mentioned bracket having two angularly related lugs thereon in vertical planes, one of which projects over and engages the head end of the hinge pintle to limit upward displacement thereof and the other of which engages the adjacent side of said head to assume side thrust of the cylinder on the hinge.

10. In a device of the character described, a cylinder containing an incompressible liiuid, a piston reciprocable in said cylinder having a rod extending from one end of said cylinder through a guide opening provided therein, whereby chambers to contain said liinid 'are defined in said cylinder on opposite sides of said piston, a coiled compression spring compressible between the other end of said cylinder and said piston, means for pivotally connecting the outer end of said rod and the remote end of said cylinder to a door and a door frame, respectively, said piston having ya port provided therein through which relatively unrestricted communication is afforded through the piston with the chambers on opposite sides thereof, there being another port provided in said piston affording relatively restricted communication through said piston between said chambers on opposite sides thereof, and a check valve housed in said piston for closing the first mentioned port, said check valve moving toward said spring to close said port, the means for pivotally connecting the remote end of said cylinder tothe door frame comprisinga bracket having a cylinder pivot on one portion thereof and having means provided on another portion thereof spaced from the cylinder pivot and adapted to be attached to a door hinge, whereby to pivotally connect the cylinder with the door frame on which the hinge is mounted with the pivot spaced radially outwardly from the hinge and hinged edge of the door, and a boxlike housing of elongated form applicable over the cylinder and projecting piston rod for concealment thereof from view in front of the door. j

11. A device as set forth in claim 1 wherein the device is applicable to a door mounted in a door frame on hinges, each of which comprises a fixed butt on the door `frame pivotally'connectedby means of a pintle with a butt secured to the door, said bracket being swingable freely relative to said pintle in the opposite direction, and a housing of elongated form applicable over the cylinder and projecting piston rod for concealment thereof from view in front of the door, said housing having an end wall adjacent the cylinder pivot on said bracket, said end wall serving by abutment with said bracket to limit its pivotal movement in the latter direction so as to limit the extent to which the cylinder pivot is movable inwardly from a dead center line through the hinge pintle and pivotal connection for the outer end of said rod on said door.

12. in a device of the character described, a cylinder containing an incompressible fluid, a piston reciprocable in said cylinder having a rod extending from one end of said cylinder through a guide opening provided therein, whereby chambers to contain said fluid are defined in said cylinder on opposite sides of said piston, a coiled; cornpression spring compressible between the other end of said cylinder and said piston, means for pivotally connecting the outer end of said rod and the remote end ofsaid cylinder to a door and a door frame, respectively, said piston having a port provided therein through which relatively unrestricted communication is afforded through the piston with the chambers on opposite sides thereof, there being another port provided in said piston affording relatively restricted communication throngh said piston between said chambers on opposite sides thereof, and a check valve housed in said piston for closing the first mentioned port, said check valve moving toward said spring to close said port, the means for. pivotally con ecting the remote end of said cylinder to the door frame comprising a bracket having a cylinder pivot on one portion thereof.

and having means provided on another portion thereof spaced from the cylinder pivot and adapted to be attached to a door hinge, whereby to pivotally connect the cylinder with the `door frame on which the hinge is mounted with the pivot spaced radially outwardly from the hinge `and hinged edge of the door and an elongated housing of: channel cross-section for application over the cylinder `and projecting piston rod to conceal the same from view from in front of the door, the side walls of said channel section being springable apart by entry therebetween of said cylinder and being resilient so as to prevent accidental displacement of the housing from assembled relationship to said cylinder, whereby the housing is held in place entirely by frictional Contact with the cylinder walls.

13. A device as set forth in claim 1 wherein the device is applicable to a door mounted in a door frame on hinges, each of which comprises a fixed butt on the door frame pivotally connected by means of a pintle with a butt secured to the door, and an elongated housing of channel cross-section for application over the cylinder and projecting piston rod to conceal the same from view from in front of the door, the side walls of said channel section being springable apart by entry therebetween of said cylinder and being resilient so as to prevent accidental displacement of the housing from assembled relationship to said cylinder, whereby the housing is held in place entirely by frictional contact with the cylinder walls, said bracket being swingable freely relative to said pintle in the opposite direction, said housing having an end wall adjacent the cylinder pivot on said bracket, said end wall serving by abutment with said-bracket to limit its pivotal movement in the latter direction so as to Vlimit the extent to which the cylinder pivot is movable inwardly from a dead center line through the hinge Vpintle and pivotal connection for the onter end of said rod on said door.

References Cited in the file of this patent UNITED STATES PATENTS 2,596,676 Goderez -May 13, 1952 2,707,798 Comey et al May l0, 1955 2,726,914 Allen Dec. 13, 1955 

1. IN A DEVICE OF THE CHARACTER DESCRIBED, A CYLINDER CONTAINING AN INCOMPRESSIBLE FLUID, A PISTON RECIPROCABLE IN SAID CYLINDER HAVING A ROD EXTENDING FROM ONE END OF SAID CYLINDER THROUGH A GUIDE OPENING PROVIDED THEREIN, WHEREBY CHAMBERS TO CONTAIN SAID FLUID ARE DEFINED IN SAID CYLINDER ON OPPOSITE SIDES OF SAID PISTON, A COILED COMPRESSION SPRING COMPRESSIBLE BETWEEN THE OTHER END OF SAID CYLINDER AND SAID PISTON, MEANS FOR PIVOTALLY CONNECTING THE OUTER END OF SAID ROD AND THE REMOTE END OF SAID CYLINDER TO A DOOR AND A DOOR FRAME, RESPECTIVELY, SAID PISTON HAVING A PORT PROVIDED THEREIN THROUGH WHICH RELATIVELY UNRESTRICTED COMMUNICATION IS AFFORDED THROUGH THE PISTON WITH THE CHAMBERS ON OPPOSITE SIDES THEREOF, THERE BEING ANOTHER PORT PROVIDED IN SAID PISTON AFFORDING RELATIVELY RESTRICTED COMMUNICATION THROUGH SAID PISTON BETWEEN SAID CHAMBERS ON OPPOSITE SIDES THEREOF, AND A CHECK VALVE HOUSED IN SAID PISTON FOR CLOSING THE FIRST MENTIONED PORT, SAID CHECK VALVE MOVING TOWARD SAID SPRING TO CLOSE SAID PORT, THE MEANS FOR PIVOTALLY CONNECTING THE REMOTE END OF SAID CYLINDER TO THE DOOR FRAME COMPRISING A BRACKET HAVING A CYLINDER PIVOT ON ONE PORTION THEREOF AND HAVING MEANS PROVIDED ON ANOTHER PORTION THEREOF SPACED FROM THE CYLINDER PIVOT AND ADAPTED TO BE ATTACHED TO A DOOR HINGE, WHEREBY TO PIVOTALLY CONNECT THE CYLINDER WITH THE DOOR FRAME ON WHICH THE HINGE IS MOUNTED WITH THE PIVOT SPACED RADIALLY OUTWARDLY FROM THE HINGE AND HINGED EDGE OF THE DOOR, THE BRACKET HAVING AN OPENING PROVIDED THEREIN TO RECEIVE THE HINGE PINTLE AND HAVING A LUG PROJECTING THEREFROM FOR ENGAGEMENT BEHIND THE FIXED BUTT OF THE DOOR HINGE IN RADIALLY SPACED RELATIONSHIP TO THE PINTLE TO PREVENT PIVOTAL MOVEMENT OF SAID BRACKET WITH RESPECT TO SAID PINTLE IN ONE DIRECTION. 